package com.hxg.server.config;

import com.hxg.server.config.security.component.JwtTokenUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.simp.config.ChannelRegistration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.messaging.simp.stomp.StompCommand;
import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
import org.springframework.messaging.support.ChannelInterceptor;
import org.springframework.messaging.support.MessageHeaderAccessor;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.util.StringUtils;
import org.springframework.web.socket.config.annotation.*;

/**
 * WebSocket配置类
 * @author Hexg
 * @date 2022/3/9 20:53
 */
@EnableWebSocketMessageBroker
@Configuration
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

    @Value("${jwt.tokenHead}")
    private String tokenHead;
    @Autowired
    private JwtTokenUtil jwtTokenUtil;
    @Autowired
    private UserDetailsService userDetailsService;

    /**
     * 添加Endpoint,这样在网页可以通过websocket连接服务
     * 也就是我们配置websocket的服务地址，并且可以指定是否使用socketJS
     * @param registry
     */
    //让前端能够连接到后端的websocket服务
    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        /**
         * 1.将ws/ep路径注册为stomp端点，用户连接了这个端点就可以进行websocket通讯，支持socketJS
         * 2.setAllowedOrigins("*")：支持跨域
         * withSockJS()：支持socketJS访问
         */
        registry.addEndpoint("/ws/ep").setAllowedOrigins("*").withSockJS();
    }

    /**
     * 正常可以不写这个方法，但是写了jwt必须在这个方法中进行处理，否则会被jwt令牌拦截器拦截
     *
     * 输入通道参数配置
     * @param registration
     */
    @Override
    public void configureClientInboundChannel(ChannelRegistration registration) {
        registration.interceptors(new ChannelInterceptor() {
            //预发送
            @Override
            public Message<?> preSend(Message<?> message, MessageChannel channel) {
                StompHeaderAccessor accessor = MessageHeaderAccessor.getAccessor(message, StompHeaderAccessor.class);
                //判断是否为连接，如果是，需要获取Token，并且设置用户对象
                if (StompCommand.CONNECT.equals(accessor.getCommand())){
                    //Auth-Token前端传的值
                    String token = accessor.getFirstNativeHeader("Auth-Token");
                    if (!StringUtils.isEmpty(token)){
                        String authToken = token.substring(tokenHead.length());
                        String userName = jwtTokenUtil.getUserNameFromToken(authToken);
                        //token中存在用户名
                        if (!StringUtils.isEmpty(userName)){
                            //登录
                            UserDetails userDetails = userDetailsService.loadUserByUsername(userName);
                            //验证token是否有效，重新设置用户对象
                            if (jwtTokenUtil.validateToken(authToken,userDetails)){
                                UsernamePasswordAuthenticationToken authenticationToken = new UsernamePasswordAuthenticationToken(userDetails,
                                        null, userDetails.getAuthorities());
                                //全局设置authenticationToken
                                SecurityContextHolder.getContext().setAuthentication(authenticationToken);
                                accessor.setUser(authenticationToken);
                            }
                        }
                    }
                }
                return message;
            }
        });
    }

    /**
     * 配置消息代理
     * @param registry
     */
    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
        //enableSimpleBroker("/queue"):配置代理域，可以配置多个，配置代理目的地的前缀为/queue，可以在配置域上给客户端推送消息
        registry.enableSimpleBroker("/queue");
    }
}
